Granted, this whole premise depends on your definition of idealized romance/relationships. I usually think of the Disneyfied version - my prince will come, happily ever after (HEA) with little to no effort, life coming up roses, etc. Very little of this applies to Pride and Prejudice - Jane & Bingley and Elizabeth & Darcy are definitely love matches, and J&B are easy going enough that their HEA might come with a minimum of fuss, but there's not a whole lot else that applies. It's for sure that E&D are going to have to work hard at their relationship, being the two stubborn, strongly-personalitied people that they are. I foresee some hum-dingers ahead for them.
Of the relationships that Austen gives us a real flavor of, the love matches (E&D, J&B, the Gardners) are far outweighed by the unhappy (Mama and Papa Bennett, Bingley's married sister), the train-wrecks-waiting-to-happen (Lydia & Wickham), the living-separate-lives-except-for-the-mar
We don't get much of an insight into the Gardners, other than the fact that they're happy, but, let's face it, Jane and Elizabeth Bennett commit to marrying for love and then work really hard for it. Jane's work took the form of waiting patiently and not completely giving up hope in the face of an apparently hopelesss situation while facing that there was very little she could actually do to influence the situation. That's hard and frustrating! Elizabeth took a slightly more active role by turning down Collin's proposal and thereby risking the wrath of her parents and the possibility that she told her only chance for independence-of-a-sort to shove off. She also had the added excitement of having feelings that needed time to mature and almost losing her chance with Darcy in the meantime. Jane and Elizabeth shared the trials that were their family and their reduced circumstances, again something to be overcome. Truly a women's extreme adventure story.